Bhutan has access to the same amount of hydropower resources as Norway, but it is still one of the poorest countries in the world where they do not talk about GDP but measure development through Gross National Happiness. For almost thirty years, Norway has collaborated closely with Bhutan to develop hydropower resources and facilitate long-term export of renewable energy to India.

"NGI is providing expert advisory services for two large hydropower projects in Bhutan in the Himalayas. Bhutan is in the process of constructing 10,000 MW of hydropower out of a total potential of 30,000 MW in the whole country", explains Rajinder Kumar Bhasin, technical expert at NGI.

Geotechnical challenges

Bhutan is indeed a mountainous country and figuring out how to build the infrastructure needed to harvest the massive amounts of hydropower is no small feat. Thus, a number of problems present themselves in the construction of the hydropower stations, Punatsangchhu P-I and P-II.

"Both are located in rugged terrain with complex geological and geotechnical conditions. The rock mass conditions are unstable and difficult to measure", explains Rajinder Kumar Bhasin.

Especially in underground constructions such as powerhouses, desilting chambers and headrace tunnels, a number of rock instabilities can occur, such as loosening of the rock mass, squeezing and spalling.

"It is not easy to predict the behaviour of the rocks due to the variation in mineral assemblages, fabric and geo-mechanical properties", says Rajinder Kumar Bhasin.

Win-win situation

Bhutan is endowed with abundant water and hydropower forms an important sector of the Bhutanese economy. The sale of hydropower accounted for the largest share of the country’s GDP. It is also the most important export item contributing about 40 percent of Bhutan’s total exports.

"NGI works for the Punatsangchhu hydropower authorities in Bhutan through the Ministry of Water Resources India. NGI is carrying out engineering geological studies including rock mass characterization and rock support design in underground constructions using numerical simulations", explains Rajinder Kumar Bhasin.

India’s support in the development of the hydropower sector in Bhutan is the centrepiece of Bhutan-India economic cooperation and is one of the main pillars of bilateral cooperation. The cooperation in the hydropower sector between the two countries enables India to alleviate their power deficiency by providing clean electricity to India, whilst generating substantial export revenue for Bhutan.

"This is indeed a sustainable win-win situation for both Bhutan and India. It makes me proud that NGI is able to contribute to the development of both countries through our geotechnical expertise, whilst promoting clean, green hydropower to one of the biggest populations in the world", says Rajinder Kumar Bhasin.

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FACTS:

  • South Asia’s considerable hydropower potential is concentrated in the Himalayan region, spanning Nepal, Bhutan and India’s northernmost states: Arunachal Pradesh, Sikkim, Uttarakhand, and Himachal Pradesh. Tapping the vast hydropower resources of Nepal and Bhutan, in particular, will be critical in order to meet the region’s rapidly growing demand in a cost-effective and environmentally sustainable manner.
     
  • Indo-Bhutan hydropower cooperation began in 1961 with the signing of the Jaldhaka agreement. The Jaldhaka project is situated on the Indian side of Indo-Bhutan border in West Bengal.
     
  • Since the late 80’s, Norway has contributed to the development of warning systems for natural hazards, systems for glacier measurements and the establishment of a hydrological data model for the country, as well being a significant contributor to the preparation of national plans for the use of Bhutan's water resources. NGI has been participating with expert advice and has been an important contributor for many years. In particular, NGI is applying analytical, empirical and observational (instrumentation) methods for verification of reinforcement design in the surface and sub-surface structures.
     
  • The current expert advisory services at the hydropower stations Punatsangchhu P-I and P-II are planned to be continued until the projects are completed in 2021.

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